A wireless local area network (WLAN) may be formed by one or more access points (APs) that provide a shared wireless communication medium for use by a number of client devices or stations (STAs). Each AP, which may correspond to a Basic Service Set (BSS), periodically broadcasts beacon frames to enable any STAs within wireless range of the AP to establish and/or maintain a communication link with the WLAN. In a typical WLAN, only one STA may use the wireless medium at any given time, and each STA may be associated with only one AP at a time. Due to the increasing ubiquity of wireless networks, when a STA seeks to join a wireless network, the STA may have a choice between multiple wireless networks and/or between multiple APs that form an extended BSS. Further, many home wireless networks employ a root AP (e.g., a base station) and multiple relay devices (e.g., “repeaters”) to extend the effective wireless coverage area of the root AP. As the STA is moved into the coverage area of one or more wireless networks, the STA may select the best AP with which to associate. After the STA becomes associated with the selected AP, the STA may be moved within and/or between the coverage area of the one or more wireless networks, and may subsequently benefit from switching its association from the selected AP to one of a number of candidate APs (e.g., APs with which the STA is not associated).
Accordingly, it is desirable for the STA to be able to quickly determine the best available AP with which to associate, regardless of whether the STA is associated with the available APs.
Like reference numerals refer to corresponding parts throughout the drawing figures.